September weather forecastBethalto, IL
September
Weather in September
The first month of the autumn, September, is also a moderately hot month in Bethalto, Illinois, with an average temperature fluctuating between 78.6°F (25.9°C) and 59.4°F (15.2°C).Temperature
With the beginning of September, the average high-temperature shows a small decrease, transitioning from a moderately hot 84°F (28.9°C) in August to a still warm 78.6°F (25.9°C). The nights of September in Bethalto, Illinois, anticipate an average low-temperature of 59.4°F (15.2°C).Humidity
In September, the average relative humidity is 75%.Rainfall
In Bethalto, in September, it is raining for 11.8 days, with typically 1.69" (43mm) of accumulated precipitation. In Bethalto, Illinois, during the entire year, the rain falls for 138 days and collects up to 23.9" (607mm) of precipitation.Snowfall
In Bethalto, snow does not fall in May through October.Daylight
In Bethalto, the average length of the day in September is 12h and 26min.On the first day of September in Bethalto, sunrise is at 6:29 am and sunset at 7:30 pm. On the last day of the month, sunrise is at 6:55 am and sunset at 6:43 pm CDT.
Sunshine
In September, the average sunshine is 9.3h.UV index
In Bethalto, the average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV rays for the average person.Note: In September, the maximum UV index of 5 suggests these recommendations:
Undertake precautions - Guarding against sun damage is counselled. Avoiding direct sunlight during midday hours helps reduce the risk from intense UV radiation. Stay sun-safe with clothing that is both closely woven and worn loosely.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Bethalto, IL
- Average high temperature in September: 78.6°F
The warmest month (with the highest average high temperature) is July (85.3°F).
The month with the lowest average high temperature is January (36.1°F).
- Average low temperature in September: 59.4°F
The month with the highest average low temperature is July (67.6°F).
The coldest month (with the lowest average low temperature) is January (23.4°F).
Average pressure in September
Bethalto, IL
- Average pressure in September: 30.02"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in September
Bethalto, IL
- Average wind speed in September: 6.3mph
The windiest months (with the highest average wind speed) are January and February (9.6mph).
The calmest month (with the lowest average wind speed) is July (5.7mph).
Average humidity in September
Bethalto, IL
- Average humidity in September: 75%
The month with the highest relative humidity is July (80%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
Bethalto, IL
- Average rainfall in September: 1.69"
The wettest month (with the highest rainfall) is May (3.07").
The driest month (with the least rainfall) is February (1.14").
Average rainfall days in September
Bethalto, IL
- Average rainfall days in September: 11.8 days
The month with the highest number of rainy days is May (16.6 days).
The month with the least rainy days is January (5.6 days).
Average snowfall in September
Bethalto, IL
- Average snowfall in September: 0"
The month with the highest snowfall is February (1.61").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Bethalto, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (6 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Bethalto, IL
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in September: 9h and 18min
The month with the most sunshine is June (Average sunshine: 10h and 24min).
The months with the least sunshine are January and February (Average sunshine: 4h and 30min).
Average sunshine days in September
Bethalto, IL
- Average sunshine days in September: 15.7 days
The month with the most sunshine days is December (20.4 days).
The month with the least sunshine days is July (12.3 days).
Average UV index in September
Bethalto, IL
- Average UV index in September: 5
The months with the highest UV index are May, June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Bethalto, IL
- Average cloud cover in September: 30
The month with the most cloud cover is January (Cloud cover 51).
The months with the least cloud cover are June, July and August (Cloud cover 29).
Average visibility in September
Bethalto, IL
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
